Exhibit 31.1

Certification of the Principal Executive Officer
Pursuant to 15 U.S.C. 78m(a) or 78o(d)
(Section 302 of the Sarbanes-Oxley Act of 2002)

I, Glenn F. Tilton, the Chairman, President and Chief Executive Officer of United Air Lines, Inc. (the "Company"), certify that:

(1)     I have reviewed this quarterly report on Form 10-Q for the quarter ended September
         30, 2004 of the Company;

(2)     Based on my knowledge, this report does not contain any untrue statement of a material
          fact or omit to state a material fact necessary to make the statements made, in light
         of the circumstances under which such statements were made, not misleading with
         respect to the period covered by this report;

(3)     Based on my knowledge, the financial statements, and other financial information
          included in this report, fairly present in all material respects the financial condition, results
         of operations and cash flows of the Company as of, and for, the periods presented in
         this report;

(4)     The Company's other certifying officer and I are responsible for establishing and
          maintaining disclosure controls and procedures (as defined in Exchange Act Rules
          13a-15(e) and 15d-15(e)) for the Company and we have:
 

(a)     Designed such disclosure controls and procedures, or caused such
         disclosure controls and procedures to be designed under our supervision, to
         ensure that material information relating to the Company, including its
         consolidated subsidiaries, is made known to us by others within those
         entities, particularly during the period in which this report is being prepared;

(b)     Evaluated the effectiveness of the Company's disclosure controls and
         procedures and presented in this report our conclusions about the
         effectiveness of the disclosure controls and procedures, as of the end of the
         period covered by this report based on such evaluation; and

(c)     Disclosed in this report any change in the Company's internal control over
         financial reporting that occurred during the Company's most recent fiscal
         quarter that has materially affected, or is reasonably likely to materially
         affect, the Company's internal control over financial reporting; and
 

(5)     The Company's other certifying officer and I have disclosed, based on our most recent
         evaluation of internal control over financial reporting, to the Company's auditors and the
         audit committee of Company's board of directors (or persons performing the equivalent
         functions):
  (a)     All significant deficiencies and material weaknesses in the design or
         operation of internal control over financial reporting which are reasonably
         likely to adversely affect the Company's ability to record, process,
         summarize and report financial information; and

(b)     Any fraud, whether or not material, that involves management or other
         employees who have a significant role in the Company's internal control
         over financial reporting.
 
 
 

/s/ Glenn F. Tilton
Glenn F. Tilton
United Air Lines, Inc.
Chairman, President and Chief Executive Officer

November 8, 2004